单例模式的学习与简单应用

　　昨天晚上睡觉的时候，偶尔浏览了一下单例模式，听说了好久，也没有正真用心去看，没想到今天和同事交流的时候发现自己记得还是比较清楚。只是对于实际应用没有练习过，转没记一篇，边学边补充。

　　

class Singleton{
    private static Singleton instance = new Singleton();
    private String name;
    
    private Singleton(){};
    public static Singleton getInstance(){
        return instance;
    }

    public String  getName(){
        return name;
    }
    public void setName(String name){
        this.name = name;
    }
    public void printInfo(){
        System.out.println("name is "+ name);
    }

}

public class TestMain{
    public static void main(String[] args){
        Singleton tsa = Singleton.getInstance();
        
        Singleton ts2 = Singleton.getInstance();
        ts2.setName("bilibili");
        tsa.setName("a234");

        tsa.printInfo();
        ts2.printInfo();

        System.out.println(tsa == ts2?"单例模式成功":"失败");
        
    }
}

自己进行参考代码重复时出现的问题：

　　

public class Singleton{
    private static Singleton instance = new Singleton();
    private Singleton(){};
    public static Singleton getInstance(){
        return instance;
    }
}
public String  getName(){
    return name;
}
public void setName(){
    this.name = name;
}
public void printInfo(){
    System.out.println("name is "+ name);
}



public class TestMain{
    public staic void main(String[] args){
        TestString ts1 = Singleton.getInstance();
        ts1.setName("基础");
        TestString ts2 = Singleton.getInstance();
        ts2.setName("bilibili");

        ts1.printInfo();
        ts2.printInfo();

        System.out.println(ts1 == ts2?"无知":"失败");
        
    }
}

　　1、连最基本的Java基础都没有了，对于基本的public类的理解都是空白；

　　2、方法属性什么的在脑子里根本就没有概念；

　　3、什么叫作无知；

　　…………

参看文章：http://blog.csdn.net/jason0539/article/details/23297037

　　

class TestSingleton {  
    String name = null;  
  
        private TestSingleton() {  
    }  
  
    private static volatile TestSingleton instance = null;  
  
    public static TestSingleton getInstance() {  
           if (instance == null) {    
             synchronized (TestSingleton.class) {    
                if (instance == null) {    
                    instance = new TestSingleton();   
                }    
             }    
           }   
           return instance;  
    }  
  
    public String getName() {  
        return name;  
    }  
  
    public void setName(String name) {  
        this.name = name;  
    }  
  
    public void printInfo() {  
        System.out.println("the name is " + name);  
    }  
  
}  

public class TestMain{
    public static void main(String[] args){
        TestSingleton ts1 = TestSingleton.getInstance();
        ts1.setName("a234");
        TestSingleton ts2 = TestSingleton.getInstance();
        ts2.setName("Data");
        

        ts1.printInfo();
        ts2.printInfo();

        System.out.println(ts1 == ts2);
        
    }
}

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